High storage capacity and separation selectivity for C2hydrocarbons over methane in the metal-organic framework Cu-TDPAT

We report on the storage capacity and separation selectivity of an rht-type metal-organic framework, Cu-TDPAT [TDPAT = 2,4,6-tris(3,5-dicarboxylphenylamino)-1,3,5-triazine], for C2hydrocarbons over CH4. Henry's constant, the isosteric heat of adsorption and the ideal adsorbed solution theory selectivity were calculated based on single-component sorption isotherms. Theoretical calculations indicate that both the open metal sites and the Lewis basic sites have strong interactions with the C2molecules. The combination of these two kinds of sites lead to the highest C2H2-CH4selectivity of 127.1 as well as record high values for C2H4adsorption enthalpies. To mimic real-world conditions, breakthrough experiments were conducted on an equimolar four-component mixture containing C2H2, C2H4, C2H6and CH4at room temperature and 1 atm pressure. Our results show that Cu-TDPAT is a promising candidate for CH4capture and purification. This journal is